Closure seals



Nov. 23, 1965 n w. H HADLEY ETAL 3,219,223

CLOSURE SEALS Filed Jan. 16, 1964 3 Sheets-Sheet 1 l NOW 23, 1965 w. H. HADLEY ETAL 3,219,223

CLOSURE SEALS Filed Jan. 16, 1964 .'5 Sheets-Sheet 2 m n n n 'n m m .n wa

f A TTORIVEY)` I NOV 23, 1965 w. H. HADLEY ETAL 3,219,223 l CLOSURE SEALS Filed Jan. 16, 1964 3 Sheets-Sheet 3 United States Patent O 3,219,223 CLOSURE SEALS William H. Hadley, Lichfield, and Ronald L. Wilton, West Bromwich, England, assignors to Metal Closures Limited, West Bromwich, England, a British company Filed `lan. 16, 1964, Ser. No. 338,075 Claims priority, application Great Britain, May 10, 1963, 18,548/63 2 Claims. (Cl. 21S-42) The present invention relates to improvements in closure caps for containers having externally threaded necks and in particular to vacuum caps for such containers.

In self-service stores there is a tendency for some shoppers to attempt to inspect the contents of goods contained in screw-topped jars and the results of such tampering can be extremely serious with products, such as sieved baby-foods, which must be maintained unexposed to air until they are used.

A variety of different known forms of closure caps may be utilised to seal and externally screw-threaded container to prevent abstraction of the contents or tampering with the contents until a security band has been broken away from the main part of the closure cap, which has a screwthreaded skirt in engagement with the thread on the container neck.

Although a normal closure of the above type might be thought to provide a complete answer to the problem arising out of tampering with a screw-threaded vacuum-sealed container, if the closure cap were applied to the container under vacuum-sealing conditions, this is found in practice not to give entirely dependable results under all conditions.

One Well known form of closure cap of the type in question is the well-known Pilferproof closure cap described in British Patent No. 369,494. The closure cap described in that patent is applied to an externally screwthreaded bottle by a rolling process and is formed of a shell of thin ductile metal, such as light gauge aluminium. It has a top and a skirt formed of an upper portion, which, although it may be prethreaded, is usually thread-rolled into engagement with thread on the bottle neck during application to a bottle, and a lower portion which, in application to a bottle, is rolled into engagement under a rib on the bottle neck to act as a security band. An interrupted slit line forms a boundary between the upper portion and lower portion of the skirt so that they are connected :to each other only by a series of angularly spaced bridges. When a suflicient torque is applied to the upper portion of the closure cap in the unscrewing direction, the bridges rupture, leaving the security band anchored under the rib on the bottle neck.

As noted above the lower portion of the skirt of the closure cap is rolled under a rib or collar on the bottle neck during application to provide a locking ring or security band. It is impossible to be certain that the vacuum seal between a Pilferproof closure cap and a glass container will not be broken before the bridges rupture and it is, in fact, possible to break the vacuum in many instances without rupturing the bridges at all. This could be particularly dangerous because the intact closure cap disguses the fact that the contents of the container have been exposed to atmosphere.

Another form of closure cap is `of the same general type as that described in British Patents Nos. 814,437 and 895,191 which incorporates a security band, which must be borne away from the threaded upper part of the skirt of the closure cap before such threaded part can be removed from the container. This closure cap is open to the same objection when applied as a vacuum seal.

above noted difculty may be overcome by providing, on an externally screw-threaded container, a two-piece closure cap, comprising a disc-like vacuum cap member, adapted to seal against the mouth of a container, and an outer closure shell having a threaded skirt and a security band at the lower margin of the skirt, said security band being engaged with a co-operating formation on the container to prevent the closure lshell from being removed from the container without at least partial separation of the security band from the skirt of the closure shell, the vaccum cap member being arranged so as to remain in undisturbed sealing relation with the container on unscrewing of the said outer closure shell until the degree of separation of the security band from the skirt of the closure shell, necessary to permit removal of the closure shell from the container, has taken place.

Preferably the disc-like vacuum cap member is trapped in a groove in the skirt of the closure shell, so as to give it a small amount of freedom of movement in the outer closure shell in the longitudinal direction, this degree of freedom of movement being greater than the longitudinal movement of the outer closure shell on the container that can be obtained without at least partially rupturing the connection between the security band and the skirt of the outer closure shell. In this manner it is possible to ensure that the seal between vacuum cap member and the container cannot be broken until the security band has been ruptured, thus making it Iobvious that the goods have been tampered with. Where the closure shell is provided with a security band connected to the threaded closure skirt by a number of spaced bridges, as described in British Patent No. 369,494, an additional advantage of the arrangement is that the extra opening torque required to lift the vacuum cap member to break the vacuum does not have to be applied at :the same moment as the extra torque required to rupture the bridges, as might be required were a one-piece pilferproof closure cap to be used as a vacuum seal. This is a substantial advantage because the size of a pilferproof closure cap required for a glass jar for babyfoods, for example, is considerably larger than conventional pilferproof closure caps for bottles and in consequence the force required to rupture the bridges is greater.

Preferably the vacuum cap member is in :the form of a disc, carrying a gasket of llowed-on polyvinyl chloride or other plastic sealing compound at or near its periphery, the edge of the vacuum cap member being trapped between the top of the outer closure shell and a rib formed in the upper part of the skirt of the shell at a level above the level of the screw-thread or above the level to which the skirt will be deformed by the formation of screwthread therein by rolling the skirt into conformity with the external screw-thread on the container neck.

To economise in the use of metal the central area yof the top of the pilferproof closure shell is cut-out, leaving only an annular shoulder at the periphery so as to hold down the vacuum cap member against the mouth of the container whilst the vacuum is forming during the cooling of the contents of the jar and prevent the vacuum cap member from being tampered with in any manner which is not apparent on visual inspection.

According to another aspect of the invention a method of packing goods under vacuum and sealing the same to render harmful tampering obvious on visual inspection comprises packing the goods in a heated condition in a Container, having an externally screw-threaded neck, holding a vacuum cap member in sealing relationship with said container around the mouth thereof, whilst a partial vacuum develops in said container, pressing down against said Vacuum cap member an outer closure shell having a top and a skirt, which terminates in a security band defined from the start by a line of weakening, rolling thread in the skirt to engage the thread on the container and engaging said security band with a yco-operating formation on said container to hold said outer closure shell against unscrewing movement on said container, whereby said outer closure shell remains anchored to said container until said security band is at least partially broken away from the skirt of the outer closure shell to reveal that the closure shell has been tampered with.

Various constructions of closure caps made in accordance with the invention are hereinafter described with reference to the accompanying drawings, wherein:

FIGURE l shows one form of closure cap, partly in section, in the unapplied condition,

FIGURE 2 shows the same form of closure cap after application to .a screw threaded container,

FIGURES 3, 4 and 5 show alternative forms of closure cap after application to a screw threaded container and FIGURES 6 and 7 are fragmentary views of alternative forms of vacuum cap member and correspondingly shaped glass jar to permit easy stacking,

FIGURE 8 is a fragmentary view of a modified form of closure shell and correspondingly shaped glass jar.

The closure cap illustrated in FIGURES 1 and 2 takes the form of an outer metal shell 1, in the top end of which there is carried a vacuum sealing disc 2, on which any suitable form of gasket may be placed. In the drawing the vacuum sealing disc 2 is shown as having an annular recess 3 in which a flowed-in gasket is formed by conventional techniques. Alternatively the gasket may be formed in the known manner from extruded polyvinyl chloride tape.

The outer metal shell 1 is made as a pressing from llight gauge aluminium container sheet and comprises an annular top flange 4 and a skirt 5. The skirt 5 has a locking ring or security band portion 6 at its lower edge, which is marked off from the remainder of the skirt by an interrupted slit line 7, in which are provided bridges 8. The upper part of the skirt has a small diameter portion 9 which is adapted to iit fairly closely over the threads on the neck of the glassware, when such threads are at the maximum size permitted by the glassware specification. The small diameter portion 9 is the portion of the skirt intended to be deformed by thread rolling to engage with the threads on the glassware. Above the portion 9 there is a portion 10 which is separated from the portion 9 by an inwardly directed rolled rib 11 which serves to retain the vacuum sealing disc 2 in the shell 1. Below the portion 9, the skirt widens out into a portion 14, having the same diameter as the locking ring portion 6 and separated from the portion 9 by a step -or shoulder 15. It will thus be seen that the portion 9, which is to be deformed by the thread rolling operation is defined at the top by the rib 11 and at the bottom by the shoulder 15. This arrangement localises the effects of the thread rolling operation and reduces the strains produced thereby on the bridges 6.

A further advantage arising out of the fact that the diameter of the locking ring portion 6 and of the portion 14 is greater than that of the portions 9 and 10 is that the closure caps may be partially nested in one another, leading to considerable space saving for transport purposes, and furthermore to simplified handling in the machinery, used to apply the closure caps to containers.

Whilst the outer shell 1 of the closure cap described with reference to FIGURES 1 and 2 is conventional in its general principles of operation, it would be possible to construct it in alternative ways, provided these included some form of locking ring at the lower edge requiring to be broken away before the vacuum sealing disc 2 could be removed, thus necessarily indicating tampering in any case where the vacuum seal has been broken.

Where the jars, to which the closures are to be applied, are returnable, the locking ring may be constructed so as to break away automatically from the jar as part of the unscrewing operation. Particularly the pilferproof closure shell may be provided with the arrangement of bridges and with the weakened or severed locking ring described in our copending British patent application No. Z193/ 62. In that construction the security 'band is split at a cut line, which extends obliquely across the security band and meets the interrupted slit line, which defines the upper edge of the security band, .at the gap between two bridges, which are positioned very close to each other. One of these brid-ges is stronger than all the other bridges, :and does not rupture when the closure shell is unscrewed, so that the security band remains attached to the skirt by the one unbroken bridge.

During application to a container, the closure cap is subjected to axial pressure, as is conventional, to hold the sealing disc 2 in sealing engagement with the container, whilst thread is formed in the portion 9 by rolling the metal of the portion 9 into conformity, with the thread on the external surface of the neck of the container and the lower edge of the security band 6 is turned under the rib on the container.

Referring to FIGURE 2, it will be seen that in the thread rolling operation, by which the material of the portion 9 of the skirt is deformed to engage with the thread 9' on the container neck, the diameter of the skirt is effectively reduced immediately below the rib 11, so that after the thread rolling operation the vacuum cap member 2 is more securely held within the outer metal shell than would appear from FIGURE l. Simultaneously with the formation of the thread in the portion 9 of the skirt, the lower marginal portion of the locking ring or security band 6 is tucked under the rib 6' on the container by known means. The known means apply metal closure shells of the present general type to a container in such a manner that the closure shell can only be turned through a very small angle before it is arrested by the contact of the locking ring 6 with the undersurface of the rib on the glass container and further turning movement is thereafter only possible by applying suicient torque to rupture the bridges 8.

In the present construction the vacuum closure cap 2 is out of contact with the rib 11 on the metal closure shell until the rupture of the bridges 8 permits the outer shell to be unscrewed sufficiently to bring the rib 11 into Contact with the peripheral edge of the cap 2. It will be seen that further turning of the shell will have a camaction to lift the cap 2. Since a relatively high torque must be applied to the shell to rupture the bridges 8, immediately after the rupture of the bridges 8, the closure shell will be turning with a relatively high momentum and at this point the rib 11 comes into contact with the closure cap 2 and this, of course, assists in breaking the seal between the closure cap 2 and the mouth of the container.

Before the application of the closure cap to a container, the ribI 11 serves only to retain the vacuum closure cap 2 within the outer shell and in fact the rib 11 may be dispensed with, if means are provided for holding the cap 2 within the shell before application. It is however essential that, after application the shell 1 should be movable along the thread until resisted by the locking ring 6, without imposing a camming effect on the closure cap 2. It would be possible to modify the closure cap shown in FIGURE 1 by utilising a light adhesive bond between the top edge portion of the vacuum closure cap 2 and the undersurface of the flange 4, provided that during application, the diameter of the upper part of the closure skirt is deformed up to a suitable level, corresponding with that of the rib 11.

In some instances it may be satisfactory to form a vacuum seal over the contents of a container by applying a vacuum sealing disc, which is separate from the outer closure shell. Thus a container may be vacuum sealed by placing a vacuum sealing disc, identical with the disc 2, over the mouth of the container at a first station and placing over it at a second station an outer shell, identical with the outer shell 1 except that the rib 11 is omitted. Thread is then formed in the portion 9 of the skirt and the security band 6 is tucked under the rib on the container neck as before.

It will be observed that the operation of rolling thread into the portion 9 of the outer closure shell reduces its diameter so that the disc 2 is trapped above the thread in an annular recess, in which it has a substantial degree of freedom of movement, because the thread does not extend up to the top of the neck of the container. The unscrewing of the shell 1, after rupture of the bridges 7 in the line of weakening separating the upper portion 9 from the security band 6, will automatically lift the disc 2 and thus break the vacuum seal.

Referring now to FIGURE 3 the closure there shown differs only from that shown in FIGURES 1 and 2 in that it has been adapted for tment to a container in which the external diameter of the rib 6 is the same as the external diameter of the thread 9. In consequence the upper portion of the skirt, in which the thread is formed, has approximately the same diameter, before the thread rolling operation, as the diameter of the security band.

The construction of closure cap shown in FIGURE 4 differs from that shown in FIGURES 1 and 2 in that it has been designed for itment to a container having the same characteristics as that to which the closure cap of FIG- URE 3 is secured. In this construction a modied security band 26 is employed. The locking band 26 has an upper score line 27 and a lower score line 28, which extend around the periphery of the shell and terminate at a cut out 30, in which lies a tongue 29. It will be apparent that the security band 26 may be broken away by pulling on the tongue 29 and severing the security band 26 along the score lines 27 and 28.

The construction of closure cap shown in FIGURE 5 employs a sealing disc 2, identical with that shown in FIGURE 1, but employs a modified form of security band 36, which is connected to the upper part of the skirt by bridges 7 in a discontinuous slit line. The security band 36 has a number of outwardly or inwardly directed projections 37, which are engageable with corresponding formations on the neck of the container. The advantage of this arrangement is that there is no operation required to be performed on the security band during application of the closure cap to a container whilst the thread in the closure caps illustrated in FIGURES 2, 3 and 4 could be preformed before the outer shell is tted to the container, in the case of the construction of FIGURE 5, the thread in the upper portion of the skirt can only be formed when the outer shell is in situ on the container.

In FIGURE 6 the outer shell 1 and disc 2 are shaped as shown in FIGURE 1. Here the bottom end of the container is shaped so that the bottom of the container rests in the recessed central area of the disc 2, whilst the container is located against substantial lateral movement by the inner edge of the annular top flange 4, which contacts an inclined surface 61 on the container.

In FIGURE 7 a modified disc 72 is employed, providing an annular platform 73, on which the container stands. The container is provided with a cylindrical surface 74 to engage with the inner edge of the ange 4 and thus locate the container against lateral movement.

In the construction of FIGURE 8 a modified outer 6 shell 81 is employed. The bottom end of the container is shaped in the same manner as is shown in FIGURE 6. In this case the shell 81 is provided with a rib 82 to engage with the inclined surface on the container.

We claim:

1. A two-piece blank for forming a vacuum seal with an externally screw-threaded container comprising a disclike rigid vacuum cap member, gasket means carried on one face of said cap member for sealing against the mouth of said container, an outer cup-shaped closure shell member, formed of thin deformable ductile metal and comprising a top having a central aperture therein of less diameter than said cap member, and a skirt adapted to have screw thread formed therein by being inwardly deformed between adjacent thread formations on the container, a security band at the lower margin of said skirt for engagement under a shoulder on the container, said skirt having a weakened portion between said security band and the upper part of the skirt, and a shoulder in said skirt defining a groove between the top of said closure shell member and said shoulder with the edge of said vacuum cap member being trapped in the groove, the dimension of said groove between said top and said shoulder being greater than that of the edge of said vacuum cap member, whereby unscrewing movement of said cap after thread has been formed in said skirt will result in raising said cap member out of engagement with the container mouth only after a predetermined angular movement of said closure shell in the unscrewing direction.

2. A closure cap for vacuum sealing an externally screw-threaded container, comprising a disc-like substantially rigid vacuum cap member, gasket means on one face of the cap member for sealing against the mouth of the container, an outer cup-shaped closure shell member formed of thin deformable ductile metal and comprising a top, a threaded skirt for engagement with the threads of the container, and a security band at the lower margin of the skirt for engagement under a shoulder on the container, said skirt having a weakened portion between said security band and the upper part of the skirt, and a shoulder in said skirt dening a groove between the top of said closure shell member and said shoulder with the edge of said vacuum cap member being trapped in the groove, the dimension of said groove between said top and said shoulder being greater than that of the edge of said vacuum cap member, whereby unscrewing movement of said cap after thread has been formed in said skirt will result in raising said cap member out of engagement with the container mouth only after a predetermined angular movement of said closure shell in the unscrewing direction.

References Cited by the Examiner UNITED STATES PATENTS 666,139 1/1901 Hay 21S-97 2,008,593 7/1935 Pedersen 215-97 2,056,778 10/1936 Fabrice 21S-42 2,280,724 4/ 1942 Sharp 21S-42 2,362,009 11/1944 Hogg 53-16 2,643,015 6/1953 Soifer 21S-42 2,802,322 8/1957 Podesta 53-16 THERON E. CONDON, Primary Examiner.

FRANKLIN T. GARRETT, Examiner. 

1. A TWO-PIECE BLANK FOR FORMING A VACUUM SEAL WITH AN EXTERNALLY SCREW-THREADED CONTAINER COMPRISING A DISCLIKE RIGID VACUUM CAP MEMBER, GASKET MEANS CARRIED ON ONE FACE OF SAID CAP MEMBER FOR SEALING AGAINST THE MOUTH OF SAID CONTAINER, AN OUTER CUP-SHAPED CLOSURE SHELL MEMBER, FORMED OF THIN DEFORMABLE DUCTILE METAL AND COMPRISING A TOP HAVING A CENTRAL APERTURE THEREIN OF LESS DIAMETER THAN SAID CAP MEMBER, AND A SKIRT ADAPTED TO HAVE A SCREW THREAD FORMED THEREIN BY BEING INWARDLY DEFORMED BETWEEN ADJACENT THREAD FORMATIONS ON THE CONTAINER, A SECURITY BAND AT THE LOWER MARGIN OF SAID SKIRT FOR ENGAGEMENT UNDER A SHOULDER ON THE CONTAINER, SAID SKIRT HAVING A WEAKENED PORTION BETWEEN SAID SECURITY BAND AND THE UPPER PART OF THE SKIRT, AND A SHOULDER IN SAID SKIRT DEFINING A GROOVE BETWEEN THE TOP OF SAID CLOSURE SHELL MEMBER AND SAID SHOULDER WITH THE EDGE OF SAID VACUUM CAP MEMBER BEING TRAPPED IN THE GROOVE, THE DIMENSION OF SAID GROOVE BETWEEN SAID TOP AND SAID SHOULDER BEING GREATER THAN THAT OF THE EDGE OF SAID VACUUM CAP MEMBER, WHEREBY UNSCREWING MOVEMENT OF SAID CAP AFTER THREAD HAS BEEN FORMED IN SAID SKIRT WILL RESULT IN RAISING SAID CAP MEMBER OUT OF ENGAGEMENT WITH THE CONTAINER MOUTH ONLY AFTER A PREDETERMINED ANGULAR MOVEMENT OF SAID CLOSURE SHELL IN THE UNSCREWING DIRECTION. 